WO2017073826A1 - Super absorbent zero gel dressing for treating wound - Google Patents

Abstract

The present invention relates to a super absorbent Zero Gel dressing material for treating a wound, and more specifically to a super absorbent Zero Gel dressing material for treating a wound having high absorbency and low adhesiveness. The Zero Gel of Zero Gel dressing material according to the present invention comprises: 10-40 wt% purified water; 45-80 wt% plasticizer; 8-13 wt% water-soluble polymer; and 0.01-5 wt% cross-linking agent. The Zero Gel of dressing material according to the present invention, being a cross-linked body having a three-dimensional networked structure, has low water content and thus enhances the absorption of exudate, has fast wound treating effect and very low adhesiveness, is thin to not stick to the wound and thus causes almost no pain when pulled off, does not leave residual material, treats the wound area smoothly as a moist environment is created due to a large amount of plasticizers, and does not produce a scab and thus produces almost no scarring post-treatment.

Description

Super Absorbent Zero Gel Dressing for Wound Care

The present invention relates to a super absorbent zero gel dressing agent for wound treatment, and more particularly, to a super absorbent zero gel dressing agent for wound treatment having a thin thickness, high absorption, and low adhesion.

Skin, which has the largest surface area in the human body, is an organ that plays an important role in protecting the body from harmful environmental conditions such as ultraviolet rays, biochemicals, etc., and controlling water vaporization and body temperature in the body. However, skin damage such as burns, trauma, wounds, bedsores, etc. occur frequently in daily life, and if left undamaged skin can cause severe defects through secondary contamination, the wound must be quickly treated to remove various side effects.

In 1962, Dr. Winter, England, found that moisturizing wounds through natural exudates (skin) from the skin rather than exposing the wounds to the air heals the wounds faster, including multinucleated white blood cells, macrophages, and proteolytic degradation. It is known to contain beneficial ingredients for various wound healing such as enzymes and cell growth factors.

When treating wounds in a dry environment such as disinfectants or gauze, the wounds are treated later because the components that heal the wounds with the disinfectant lose their activity, or they dry out by evaporation of water, causing cells to die and delay cell growth. In most cases, scarring was caused by scabs. In addition, the gauze is attached to the wound to give a trauma to the wound when replacing the dressing, there is a problem causing pain when peeling off.

On the other hand, the wet dressing agent blocks bacteria or foreign substances from the outside, activates the cell regeneration component through the exudates so that the skin regeneration epithelial cells can grow smoothly by creating a wet environment around the wound, and no scab is formed. It is effective in healing wounds quickly without scars.

As such formulations that make a wet environment useful for wound healing are known, dressing agents using hydrocolloids, polyurethane foams and hydrogels as bases.

Korean Patent Laid-Open No. 10-2015-00063223 discloses a method of preparing a hydrogel by mixing cationic materials such as chitosan and anionic materials such as carboxymethyl cellulose with electrostatic attraction. Although excellent injectable drug carriers are characterized, there is a big disadvantage of crosslinking by mixing the cationic material and anionic material in a solution state for 30 to 50 hours.

Korean Patent Publication No. 10-2014-0016450 discloses an aqueous solution of keratin derivatives by dissolving keratin derivatives extracted from the hair of animals including humans in water to prepare hydrogels having excellent biocompatibility. After adding and dissolving polyethyleneimine to prepare a mixture aqueous solution, a method of preparing a hydrogel useful for wound healing or skin regeneration by irradiating the mixture aqueous solution with radiation is disclosed. This has the advantage of being eco-friendly and biocompatible because it can produce hydrogels with minimal chemicals.However, it can be easily discolored or discolored by the production of low-molecular weight by-products for wound treatment or skin regeneration. Use as a hydrogel has an unsuitable problem.

In addition, Korean Patent No. 20-0390463 discloses a method for preparing a wound band by applying a hydrogel composed of glycerin, polyethylene glycol, purified water, sodium polyacrylate, tartaric acid, and dry aluminum hydroxide to a nonwoven fabric. , 55 to 68 parts by weight of a large amount of purified water is low because there is a limit to absorb the large amount of exudates that appear in the initial wound, there is a problem that the excessive wound environment is formed to prolong the initial wound healing time have.

Accordingly, the present inventors have made diligent efforts to solve the above problems, and when the content of purified water, water-soluble polymer, crosslinking agent and plasticizer is properly adjusted, the thickness of thin, high absorbency, and low adhesion, super absorbent zero gel dressing for wound treatment It was confirmed that the agent can be produced, and the present invention was completed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a zero gel dressing agent having a thin thickness, high water absorption, and low adhesion.

In order to achieve the above object, the present invention (a) a support; (b) a zero gel stacked on top of the support; (c) an adhesive cloth laminated on the lower portion of the support; And (d) a zero gel dressing agent comprising a release film coated on the zero gel, wherein the zero gel is 10 to 40% by weight of purified water; Plasticizer 45-80 wt%; It provides a zero gel dressing agent comprising 8 to 13% by weight of a water-soluble polymer and 0.01 to 5% by weight of a crosslinking agent.

In the present invention, the plasticizer is at least one member selected from the group consisting of glycerin, 1,3-butylene glycol, propylene glycol, sorbitol, dipropylene glycol, ethylene glycol and polyethylene glycol.

In the present invention, the water-soluble polymer is characterized in that at least one member selected from the group consisting of natural polymers, synthetic polymers and semi-synthetic polymers.

In the present invention, the crosslinking agent is at least one member selected from the group consisting of aluminum hydroxide, aluminum magnesium silicate, aluminum glycinate, aluminum chloride and aluminum sulfate.

In the present invention, the thickness of the zero gel is 100 ~ 300㎛, the adhesive strength of the zero gel according to the measurement method is less than No. 5 (diameter: 9.5mm, weight: 3.5g) of the iron beads, the absorbency is It is characterized by more than 400%.

<Measurement of adhesion force>

Zero-gel is cut into 10cm × 10cm size and the sample adhesive face up on the inclined surface by using the adhesion tester with the inclination angle of 30 ° and the length of 30cm on the inclined surface. Measure the lake of the bead when it rolls from the upper end of the slope along the lake of the iron ball.

<Absorbance measurement>

The gel was cut into 5cm × 5cm size and immersed in 25 ℃ physiological saline solution (0.9% sodium chloride solution) for 1 hour, then taken out and dried at room temperature for 10 minutes, and the weight change was measured and calculated by the following equation.

Absorption (%) = (Weight after deposition-Weight before deposition) / Weight before deposition × 100

The zero gel of the dressing agent according to the present invention is a cross-linked body of a three-dimensional network structure, which has a low water content, thereby improving the absorption function of the effusion solution, the wound healing effect is very fast, the adhesive strength is very low, and the thickness is small so that it does not stick to the wound. When you remove it, there is little pain, no residue is left, and a large amount of plasticizer creates a moisturizing environment, so the wound is smoothly treated, and there is no scab, so there is almost no scar after treatment.

1 is a photograph of a zero gel dressing agent prepared according to an embodiment of the present invention.

In the present invention, the plasticizer is a composition that is correlated with the content of purified water, and when the content of the purified water is low, the content of the plasticizer should be increased, and glycerin, 1,3-butylene glycol, propylene glycol, sorbitol, dipropylene glycol, It can be used 1 type or in mixture of 2 or more types from ethylene glycol and polyethylene glycol, and it is preferable to use 45-80 weight%. When the content of the plasticizer is less than 45% by weight, there is no flexibility, and when the content of the plasticizer exceeds 80% by weight, the viscosity becomes very sticky and the crosslinking time is long.

In the present invention, the water-soluble polymer may be a natural polymer, a synthetic polymer and a semi-synthetic polymer as one component composed of a cross-linked body of a three-dimensional network structure, and as a natural polymer, collagen, gelatin, xanthan gum, carrageenan, agar, alginic acid or salts thereof , Hyaluronic acid or salts thereof, pectin, starch and the like can be used, and synthetic polymers include polyacrylic acid or salts thereof, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, methyl vinyl ether maleic anhydride copolymer, isobutylene anhydride Maleic acid copolymer, butyl methacrylate acrylic acid copolymer, methoxy ethylene maleic anhydride copolymer, etc. may be used.As a semi-synthetic polymer, one or more components selected from sodium carboxymethyl cellulose, soluble starch, and carboxymethyl starch may be used. It is not limited.

The content of the water-soluble polymer is preferably 8 to 13% by weight. When the content of the water-soluble polymer is less than 8% by weight, the absorbency may be lowered or may be dissolved in water. When the content of the water-soluble polymer is greater than 13% by weight, the viscosity is high, so that it is difficult to formulate and difficult to apply thinly.

In the present invention, the crosslinking agent may be used in an amount of 0.01 to 5 wt% by mixing one or two or more kinds of aluminum compounds such as aluminum hydroxide, aluminum magnesium silicate, aluminum glycinate, aluminum chloride and aluminum sulfate. When the content of the crosslinking agent is out of the range, there is a problem in that it is difficult to produce a zero gel having low adhesive strength and excellent gel strength because it does not achieve optimal crosslinking with the water-soluble polymer.

Acidity regulator in the present invention has a function to control the crosslinking rate, organic acids such as citric acid, lactic acid, tartaric acid, glycolic acid and organic base such as monoethanolamine, diethanolamine, triethanolamine, diisopropanolamine It can be used, the content is preferably 0.01 to 5% by weight.

In the present invention, the reaction rate modifier may be used by mixing one or two or more of ethylenediaminetetraacetic acid and salts thereof, sodium polyacrylate (molecular weight: 10,000 or less), phosphate, and the content is 0.01 to 5% by weight. desirable.

In the present invention, preservatives may be used one or two or more of methylparaben, propylparaben, phenoxyethanol, 1,2-hexanediol, 1,2-octanediol, chlorophenesin, etc., the content of each It is recommended to use it as a standard based on the content announced by the Ministry of Food and Drug Safety.

In the present invention, the zero gel may further contain a surfactant, stabilizer, dissolution aid, pigment. Surfactants are for promoting transdermal absorption and maintaining the stability of the compositions, anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants can be used, one or two or more of these Can be used mixed.

In addition, the stabilizer may be used antioxidants such as dibutyl hydroxy toluene, sodium pyrosulfite, butyl hydroxy anisole, ascorbic acid, the dissolution aid may be selected from animal and vegetable oils or derivatives thereof. The dye may be exemplified by titanium oxide, zinc oxide, iron oxide, water-soluble dyes, pigments, etc., but is not limited thereto.

The zero gel of the present invention may use additives such as medicinal ingredients, excipients, inorganic fillers, viscosity modifiers and the like having a wound healing function in a range that does not change the physical and chemical properties of the zero gel in addition to the above components as necessary.

In the present invention, the adhesive cloth is used by attaching the support to the center to attach the zero gel to the skin, one or two kinds of nonwoven fabric, fiber, cotton, rayon, polyethylene film, polyurethane film or polyethylene phthalate film. It can be used that the adhesive was applied to one surface of the above-mentioned laminated, and it is preferable to cut and use so that the sum of both lengths may become 10-50 mm larger than the magnitude | size of a support body. If the sum of both lengths is less than 10mm, the adhesive surface to be applied to the skin is narrow, so the dressing agent is easy to fall off the skin. If the length exceeds 50mm, the adhesive surface to the skin is too wide, so the adhesive cloth can be easily removed by clothing or external friction. There is a problem in which drying occurs.

The zero gel dressing agent of the present invention may include a release film or a release paper to protect the zero gel layer directly contacting the wound from external contamination, the release film may be a transparent or white opaque polyethylene phthalate, polyethylene, polypropylene, Examples of the polyvinyl chloride and polycarbonate films may be exemplified, and the release paper may be exemplified by release of silicone, fluorine, or the like after the paper is coated with polyethylene.

It is preferable to select and use the thickness of a release film or a release paper in the range of 10-200 micrometers. Less than 10㎛ is too thin to maintain the shape of the zero gel is easy to be damaged, there is a problem that is difficult to handle because it is too thick when it exceeds 200㎛.

In the present invention, the thickness (weight conversion) of the zero gel having excellent flexibility is preferably 100 to 300 µm. If the thickness is less than 100 µm, it may be difficult to stack on the support, and the problem may be low in absorbency.

In the present invention, the adhesive force of the zero gel is characterized in that the lake of iron ball is less than 5 (diameter: 9.5mm, weight: 3.5g).

The adhesive strength of zero gel is an element that can safely treat a wound without causing pain or secondary trauma during dressing change, and can measure initial adhesive force.

That is, in the present invention, the adhesive strength of the zero gel is measured by cutting the zero gel into a size of 10 cm × 10 cm and using the adhesion tester having an inclination angle of 30 ° and an inclination surface length of 30 cm. After pasting the paper on the upper 10cm, the lower 15cm or less of the, can be measured by the lake of the marble to stop when rolled from the upper end of the slope according to the lake of the iron ball of Table 1 below.

Table 1

Lake		One	2	3	4	5	6	7	8	9
diameter	Mm	3.2	4.8	6.3	7.9	9.5	11.1	12.7	14.3	15.9
	inch	1/8	3/16	1/4	5/16	3/8	7/16	1/2	9/16	5/8
weight	g	0.13	0.45	1.00	2.00	3.50	5.60	8.30	11.90	16.30

For reference, the high cohesion of the lake of iron ball 5 or more can cause pain or secondary trauma during dressing change.

In addition, the absorbency of the zero gel is a measure of the absorption ability of the exudate having a wound healing function, the higher the absorption, the better the wound healing ability, preferably 400% or more. If it is less than 400%, initial wound treatment may be delayed, which produces a large amount of exudate.

Absorbance of the zero gel in the present invention is cut to a size of 5cm × 5cm zero gel immersed in 25 ℃ physiological saline (0.9% sodium chloride solution) for 1 hour, then taken out and dried at room temperature for 10 minutes, weighed The amount of change can be measured and calculated by the following equation.

Absorption (%) = (Weight after deposition-Weight before deposition) / Weight before deposition × 100

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention, and it will be apparent to those skilled in the art that the scope of the present invention is not to be construed as being limited by these examples.

Example  1-4 and Comparative example  1 to 3: Zero gel  Dressing agent manufacturing

In the composition (unit weight%) of Table 2, a crosslinking agent, a reaction rate regulator, a preservative, and a water-soluble polymer were added to the plasticizer to be uniformly dispersed, and then uniformly mixed with purified water in which the acidity regulator was dissolved to prepare a gel. Next, a gel was applied to a support (a nonwoven fabric having an average weight of 16 g / m 2, a 20 μm thick polyethylene film) at a constant thickness, a release film (75 μm thick transparent polyethylene phthalate film) was attached, and dried and aged to prepare a zero gel. By cutting to a constant size to prepare a gel preparation.

TABLE 2

division	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2	Comparative Example 3
Sodium polyacrylate	13.00	10.00	10.00	8.00	7.70	13.70	10.00
glycerin	50.00	48.70	45.00	80.00	80.50	44.50	79.20
Sodium Ethylenediaminetetraacetic Acid	0.30	0.30	0.30	0.50	0.30	0.30	0.30
Aluminum Magnesium Silicate	0.30	0.30	0.30	0.50	0.30	0.30	0.30
Methylparaben	0.15	0.15	0.15	0.25	0.15	0.15	0.15
Propylparaben	0.05	0.05	0.05	0.25	0.05	0.05	0.05
Tartaric acid	0.50	0.50	0.50	0.50	0.50	0.50	0.50
Purified water	35.70	40.00	33.70	10.00	10.50	40.50	9.50
Sum	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Experimental Example  1: quality evaluation

For the compositions of Examples 1 to 4 and Comparative Examples 1 to 3, the uniformity at the time of blending, the skin residue at the time of sticking, the absorbency, the adhesion and the thickness were measured.

1-1: Uniformity in Mixing (Mixed Degree)

Since the zero gel of the present invention has a characteristic that the viscosity increases with time, and there is a limit in accurately measuring the viscosity using a viscometer, the uniformity at the time of blending is observed and compared, and the results are shown in Table 3 below. Shown in

TABLE 3

division	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2	Comparative Example 3
Uniformity	◎	◎	◎	◎	○	X	X

◎: Very good ○: Good X: No fluidity, nonuniform

1-2: Affix  City skin Remnants

The zero gel dressing agents prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were cut to a size of 5 cm × 5 cm and patched to the skin of 10 subjects for 6 hours, and then the residue and stickiness were examined. The analysis was carried out on a 5-point scale, and the results are shown in Table 4.

Table 4

division	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2	Comparative Example 3
Remnants	5.0	5.0	5.0	4.8	1.5	4.5	4.0

5 points | pieces: There is no residue. 4 points | pieces: There is little residue and stickiness. 3 points | pieces: There is no residue but is a little sticky. 2 points | pieces: There is a little residue. 1 point: Remnants remain on the skin

1-3: Absorbance Measurement

The zero gel dressing agents prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were cut to a size of 5 cm × 5 cm, immersed in 25 ° C. saline (0.9% sodium chloride solution) for 1 hour, and then taken out. After drying at room temperature for minutes, the weight change was measured and calculated by the following equation, and the results are shown in Table 5.

  Absorption (%) = (Weight after deposition-Weight before deposition) / Weight before deposition × 100

Table 5

division	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2	Comparative Example 3
Absorbance (%)	524.6	501.2	460.5	429.7	Dripping	280.5	605.2

1-4: adhesive force measurement

The zero gel dressing agents prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were cut to a size of 10 cm × 10 cm, and the adhesive surface of the specimen was placed on the inclined surface using an adhesion tester having a 30 cm length of inclined angle of 30 °. Place the paper on the top 10cm and the bottom 15cm of the inclined surface facing up, and measure the lake of the marble which stops when rolling at the upper end of the slope according to the lake of the iron ball, the results are shown in Table 6. . For reference, the diameter and weight of the steel ball by lake are shown in Table 7.

Table 6

division	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2	Comparative Example 3
adhesiveness	One	One	One	3	7	5	6

TABLE 7

Lake		One	2	3	4	5	6	7	8	9
diameter	Mm	3.2	4.8	6.3	7.9	9.5	11.1	12.7	14.3	15.9
	inch	1/8	3/16	1/4	5/16	3/8	7/16	1/2	9/16	5/8
weight	g	0.13	0.45	1.00	2.00	3.50	5.60	8.30	11.90	16.30

1-5: Thickness (weight conversion) measurement

The zero gel dressing agents prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were cut to a size of 10 cm × 10 cm to accurately measure the weight of each sample, and the weight of the zero gel itself except the weight of the release film and the support. Was calculated. When the weight is 1g, the thickness of the zero gel is converted to the same as 100 μm, and the results are shown in Table 8.

Table 8

division	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2	Comparative Example 3
adhesiveness	208 ㎛	222 ㎛	220 ㎛	187 ㎛	184 ㎛	210 μm	318 ㎛

As a result of the above quality evaluation, Examples 1 to 4, Comparative Example 1 and Comparative Example 2 were excellent except for Comparative Example 3 in which the content of the purified water in the uniformity was low, and Comparative Example 1 having a high plasticizer content was Sticky and residues remained on the skin, and when absorbance was measured, the gel absorbing saline melted and ran down.

In addition, Comparative Example 2 having a high purified water content showed a relatively low water absorption. Comparative Example 3 showed a high water absorption, which is considered to be a phenomenon in which the content of purified water was low and appeared to be thickly applied.

On the other hand, Comparative Example 3, there is no residue when the skin attached, there were many opinions that the feeling of use is bad because of the heterogeneity to the thickness.

In the results of the adhesion measurement, Comparative Examples 1 to 3 were found to have high adhesion, which may cause pain and secondary trauma when attached to the wound.

Experimental Example  2: wound Therapeutic ability  evaluation

The wound healing ability of the zero gel dressing agents prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was evaluated for 30 days in the micro pigs of 3 months of age. As a breeding environment, temperature 24 ± 2 ℃, relative humidity 50 ± 10%, ventilation frequency 10 ~ 15 times (Hepa filter), contrast cycle 12 hours / day, roughness 200 lux, noise 45db and ammonia 20ppm were managed. Using the surgical mass of No. 11 and No. 12, the entire skin layer was cut out on the back of the micro pig in the size of 3 cm × 3 cm, and in M and Example 1, which were made of polyurethane foam of Company I as a control. The prepared composition was cut to a size of 5 cm x 5 cm and attached to each wound site three by three, and a 7 cm x 7 cm adhesive cloth was attached thereon so as not to be peeled off.

The composition prepared in Example 1 and the control group were exchanged every 3 days, and the wound healing ability was calculated by the following equation after measuring the size of the wound with a PET film, measuring the area of the wound with an area program, and as a result, Is shown in Table 9.

Wound Healing Effect (%) = (Initial Wound Size-Size after Wound) / Initial Wound Size x 100

Table 9

Time	Early	3 days	6 days	9th	12 days	15th	18 days	21st	24 days	27th	30 days
Example 1	0	34.9	41.2	55.6	66.7	73.6	86.7	96.4	100.0	-	-
Control	0	34.9	40.2	53.3	55.6	62.0	75.0	79.8	90.0	93.6	97.2

From Table 9, in the wound treatment effect, the control group showed a similar level as in Example 1 at the initial stage of the effusion, but after 9 days of no effusion, the wound was dried and the wound was very rough. The wound healing rate was significantly decreased.

In Example 1, the wound healing effect appeared relatively quickly even when the wound was dry, and no scab was formed on the wound, and the wound was smoothly treated. It does not produce scabs because it creates a proper moisturizing environment even in the dry state without exudates.

As described above in detail specific parts of the present invention, it will be apparent to those skilled in the art that these specific descriptions are merely preferred embodiments, and thus the scope of the present invention is not limited thereto. will be. Thus, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

The zero gel dressing agent according to the present invention does not adhere to the wound, so there is almost no pain when peeling off, no residue is left, and a large amount of plasticizer creates a moisturizing environment, so that the wound is smoothly treated, and no scabs are formed to treat it. Since there is an effect that scars hardly appear afterwards, it can be widely used as a dressing agent.

Claims (5)

1. (a) a support; (b) a zero gel stacked on top of the support; (c) an adhesive cloth laminated on the lower portion of the support; And (d) a zero gel dressing agent comprising a release film coated on the zero gel,

   The zero gel is 10 to 40% by weight of purified water; Plasticizer 45-80 wt%; Water soluble polymer 8-13% by weight; A zero gel dressing agent comprising 0.01 to 5% by weight of a crosslinking agent.
2. The zero gel dressing agent of claim 1, wherein the plasticizer is at least one selected from the group consisting of glycerin, 1,3-butylene glycol, propylene glycol, sorbitol, dipropylene glycol, ethylene glycol, and polyethylene glycol.
3. The zero gel dressing agent of claim 1, wherein the water-soluble polymer is at least one selected from the group consisting of natural polymers, synthetic polymers, and semi-synthetic polymers.
4. The zero gel dressing agent of claim 1, wherein the crosslinking agent is at least one selected from the group consisting of aluminum hydroxide, aluminum magnesium silicate, aluminum glycinate, aluminum chloride and aluminum sulfate.
5. According to claim 1, wherein the thickness of the zero gel is 100 ~ 300㎛, the adhesive strength of the zero gel according to the measurement method is less than No. 5 (diameter: 9.5mm, weight: 3.5g) of the iron ball, the absorbency The zero gel dressing agent, characterized in that more than 400%.

   <Measurement of adhesion force>

   Zero-gel is cut into 10cm × 10cm size, and the adhesive surface of the sample is placed on the inclined surface by using the adhesion tester with an inclination angle of 30 ° and the length of 30cm on the inclined surface. Measure the lake of the bead when it rolls from the upper end of the slope along the lake of the iron ball.

   

   <Absorbance measurement>

   The gel was cut into 5cm × 5cm size and immersed in 25 ℃ physiological saline solution (0.9% sodium chloride solution) for 1 hour, then taken out and dried at room temperature for 10 minutes, and the weight change was measured and calculated by the following equation.

   Absorbance (%) = (Weight after deposition-Weight before deposition) / Weight before deposition × 100

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